ไม่สามารถเล่นวิดีโอนี้
ขออภัยในความไม่สะดวก
ฝัง
- เผยแพร่เมื่อ 15 ส.ค. 2024
- Capacitors are essential to the smooth running of most circuits but can appear a little boring! Let's explore what they do, from an Arduino perspective.
Don't forget! A very useful capacitor conversion chart is available in my GitHub:
github.com/Ral...
============================
ITEMS MENTIONED IN THE VIDEO
============================
Electrolytic 200pcs 0.1-220uF 15 Value Electrolytic Capacitor Assortment Box Kit
www.banggood.c...
Multilayer Ceramic Geekcreit® 300pcs 10 Values 50V 10pF To 100nF Multilayer Ceramic Capacitor Assortment Kit 30pcs Each Value
www.banggood.c...
More expensive but good selection
500pcs 10Values*50pcs 0.1uF-10uF(104~106) 50V Multilayer Ceramic Capacitor Assorted Kit Assortment Set with Storage Box
www.banggood.c...
List of all my videos
(Special thanks to Michael Kurt Vogel for compiling this)
bit.ly/TH-camV...
If you like this video please give it a thumbs up, share it and if you're not already subscribed please consider doing so and joining me on my Arduinite journey
My channel, GitHub and blog are here:
------------------------------------------------------------------
/ ralphbacon
ralphbacon.blog
github.com/Ral...
------------------------------------------------------------------
Nicely presented, Ralph. Thank you.
My pleasure!
Nicely done presentation for you BB playlist, definitely what us newbies in the hobby are looking for.
Glad it was helpful!
Because I’m not a trained Electroics engineer and need a visual experience, I made a 555 timer circuit and changed the Cap to watch the led flash at different rates. THANKS RALPH!
Actually doing it, the way you have, makes the information stick in your brain forever. Great to hear, Mark.
Just while you uploaded this video, I hade demonstration lab with my students where I showed them the discharge curve of capacitors measured by an Arduino nano. When I wanted to upload my recording for my students I was welcomed on youtube with a link of almost the same topic 😂
The world is a small place indeed, Uwe. And great minds think alike.
Nice short video sticking well to the title and not going off the subject, very informative :-)
Glad you liked it!
Hi Ralph...
Haven't seen one of those red and black electrolytic for years!
I've just fallen over your channel and I'm binge watching it as I'm isolating 'cos I'm in the vulnerable group.
I've taken my much neglected Arduino stuff out of retirement and happily playing electronics again.
Thanks for the excellent videos, most informative and amusing at times.
Sounds like you'll be busy!
I used to get millions of those red and black (Plessey?) caps out of old tellies in the 1980s... they used to come apart really easily which was excellent for my education.
Thanks for the video! At my level of understanding, your explanation was succinct and entertaining. I'm really looking forward to your MOSFET video.
Glad it was helpful! MOSFET one in two videos' time.
Very informative. This serious definitely is informative and useful. Thanks
Glad to hear it!
Really enjoying this series
Thanks for sharing
Glad you enjoy it!
Short, clear, to the point and fun, great fun, a treat to see. Thanks, great video Ralph !
Glad you enjoyed it, John, thanks for posting.
Very useful and interesting Thanks
You are welcome!
Thank you. This video managed to hit on a bunch of capacitor uses all in one short video. I also had no idea about using Vin for higher voltages. I feel very edumicatedfied! 🙃
Glad it helped!
Very nice Ralph !
Thank you! Cheers!
Another common use for capacitors is in an RC filter circuit. E.g. if you need to delay a signal going from on to off or vice-versa, or if you need to remove high frequencies from an analog input signal to prevent aliasing.
Thanks for sharing!
Thanks Ralph. I found this very clearly presented and explained 👍
Great to hear! Good to hear from you John.
Great! exactly what i was waiting for : )
Glad to hear!
As normal rule of thumb, I never go above 80% of the cap's rated voltage to improve reliability of the design.
Agreed. What a mistake to make! But what a stupidly low voltage that 1000uF cap had!
Great mini-series, very useful for me.
Glad you like them!
+1 for the cookie cap!
Perhaps I could sell them with that name? Malted Cookie Caps!
Ralph S Bacon Hahaha! Go for it Ralph! Thanks for making and sharing these vids. Very entertaining, interesting and informative. Much appreciated.
Always something new to learn!
Glad to hear it!
Very useful. Great biscuit analogy 😁
Glad it was helpful!
Simples. Just right for me. Yay!
And no coding required! Win win!
Good one. I like the capacitor.marking charts that you've but together. Also... I found another use for a capacitor, while working on my mom's MP3 player. You could put it in the storage category, I suppose. I implemented a version of your circuit that uses a a pair of MOSFETs and an arduino output pin to control the nano's Vin. I did not want to have mom hold the "ON" button down, waiting for the arduino to take over, so I tacked a 10u across the 100k gate-source resistor. This has the effect of holding the gate on for 1.7 seconds after the "ON" button is released and giving the nano about 1.4 seconds to complete the boot process and set the "HOLD_PWR_ON" pin active.
PS: I could have programmed the boot loader out, via the ICSP port, but would have had to change much of the physical construction of the player. As it stands the USB port is easily accessable through an access hole at the back.
Yes, that is a good use for a capacitor as an energy storage device. But now you know why I almost always zap the bootloader on "production" devices and only use it whilst developing (sometimes not even then). Just as easy to use the ICSP socket.
What program do you use to draw your circuts? Been looking for a good one for a bit now. Also, great video! Very informative and it goes straight to the point. I appreciate it :)
I just use the standard Windows 10 whiteboard with a graphics tablet! Glad you liked the video too!
The power storage usage really seems like an extreme case of the decoupling usage, I know 'supercaps' are sometimes used to replace batteries. Of course the dc blocking usage can also be frequency filtering for people that know the math(s). All this is just advanced uses of the basics younlaid out. To be honest this is the first time I've truly understood decoupling caps, I always thought there was some mysterious function I didn't know.
Not really, Kent. Decoupling is to remove noise and keep the DC voltage as DC without anything superimposed on it that will upset the chip. Power storage is literally just that - like a mini battery it stores DC for when it is required.
Boy did I want to scoff that custard cream. Useful vid thanks Ralph.
You should, the next time you build something.
There is one exception to this voltage rule, in the Electrolytic Firecracker Circuit. This circuit requires the rated voltage be significantly exceeded with a hefty power supply. This circuit can only be used with serious eye-protection, because as the fragments destroy one eyeball, the involuntary blink reflex will prevent the other eye from witnessing the event, and if no one saw it happen, it didn't happen. Also it is too fast for the eye to follow.
So given the likelihood of fire, facial disfigurement, and breathing in of the (toxic?!?!?) capacitor dust, this is a very inefficient and highly discouraged form of tech entertainment.
This circuit is sometimes created unintentionally when powering up old equipment with the cover off. You can switch it on for a second and off again, several times, in hopes of letting the old caps rebuild their oxide layer. But something else may blow up.
SO WEAR A FACE SHIELD!!! Or at least safety glasses. If you are a life form with enormous compound 'insect' eyes, the hundreds of redundant lenses made of very tough proteins, the risk may deemed acceptable , but consult with a Xenobiologist knowledgeable of your species.
Finally, from the legal point of view, if you do any of these things, and any thing goes wrong, you're screwed!!!! So just don't go there.
Yes, most definitely best avoided 💥
how do we calculate the capacitance of decoupling capacitor to be used for arduino UNO?
Do we need to calculate it? 100nF seems to be the Industry Standard for decoupling Arduino power pins.
Great video. Thanks
Glad you liked it!
Hey Ralph !! Thanks for the info !! A question please !! How is the quality of those capacitors you purchased from Banggood ?? Do you/would you trust them for use in actual projects ?? Thanks for your response !!
For a home/hobbyist project then no problem.
I would not use them for a commercial project as you never know what you are getting. Are they caps that failed [Apple's] stringent quality tests but are "OK" for general use? Aside: no-one would use anything but quality suppliers for commercial projects anyway, eg Digikey, Mouser, RS Components at several times the price (probably) and bought in hundreds if not thousands of units.
I don't believe there will be anything "wrong" with Banggood components (or AliExpress, Gearbest etc) but they won't be of military spec! Good value for hobbyists!
Definitely useful AND interesting!
Glad you think so!
no overrun bang, no wrong connection bang, otherwise fine video ;-)
old black and white tv (lamp era) had gigantic capacitors, deadly
Don't remind me of old black and white TV sets (that I turned into sound to oscilloscope devices for the local disco - it was a long time ago). I have some tingles from those (= whacking my arm back at speed as it goes numb from the shock).
@@RalphBacon which song(s) was used to test, beegees/donna summer ?
You want the voltage on the capacitor to be as close as your supply voltage. I beg to differ. If you want an electrolytic cap to last, you need to derate it 50% on the voltage rating. Otherwise they'll cook.
I don't believe I said that! In my example I suggested a 10v cap for an Arduino at 5v. That's double the voltage. But many Asian products have 6v caps in Arduino-related modules (now that might explain a thing or two).
Great. I will never measure a capacitor again without wanting a custard cream now.
Exactly! Visual memory hooks like that really stick. And taste good too.
Yay the birds are back!
They were real birds I'm sure. They are right outside my window, on the bird feeders.
Very Fun to watch, just subbed.
Thanks for the sub!
You can't trick me! That's not a capacitor! It's a custard cream!
Woah! Those old (are they Plessey?) black and red ones with the yellow label. I used to get MILLIONS of those out of old tellies in the 1980s, I haven't seen one "in the flesh" this century. I saw a pack of 10 on E. Bay a few months back and was sorely tempted... not that I needed them for anything... just for pure nostalgia.
You should have mentioned that (for Australian language reasons) "Picofarads" is actually pronounced "puff". ;)
Yes, a custard cream is what it is, no doubt about it. I'm guessing today's capacitors are of better quality than those custard creams? And electrolytic caps do have a limited life (which is why electronics engineers try not to use them).
Only 10 seconds in, I’m totally distracted by the biscuit, trying to work out whether it’s a malted milk - custard cream hybrid 😂
Aaaah it’s dielectric cream. Brilliant!
Very clever! Very satisfying to eat too.
Superb quick explanations there Ralph, filled in a couple of gaps for me. Thank you!
Should be two chocolate coated malted milks paired chocolate to chocolate so it doesn’t melt on your fingers...
The chocolate is not a good insulating layer, I'm afraid.
wooow, that's gonna be useful, thanks!
Glad you think so!
Great video! Have being missing you Ralph...any new vids?
Working on it!
How about a next video about super capacitors? Best regards, keep up the great vídeos!
Great suggestion!
Thank you!
You're welcome!
perfect video
Glad you enjoyed it, Bob!
Thanks for making this. Q: I use and Arduino in a car project. It's plugged into the cig lighter via a 12V->5V buck converter, draws ~0.15 A @ 5V. No power when the engine is off. I'd like Arduino to do a small task AFTER I turned off the engine, I need to power the Arduino for ~10 sec longer. Would a capacitor (either 12V or 5V), in parallel with VCC/GND, do it? If so, what type, capacity, voltage? Thx
I'm afraid a _standard_ capacitor just wouldn't do it, as the Arduino (UNO?) draws too much current.
As it's a car you _might_ get away with a physically large and high value (multi-Farad) capacitor but even then unless your circuit has been designed to limit its power consumption it will quickly discharge. A one-million μF capacitor (1F) charged to 5v, discharging via the Arduino UNO at something like 200mA (200,000μA) down to 4V will last (maybe) 5 seconds. All very finger in the air calculations.
(Try it here: www.circuits.dk/calculator_capacitor_discharge.htm)
A better way would be to make the Arduino _permanently_ powered via the 12v-to-5v module, then via an auto on/off module (see my video #123 as a starting point, th-cam.com/video/g1rbIG2BO0U/w-d-xo.html ). This means the Arduino is powered on until it decides it can power off, and does so. You can still use the cigar lighter point as a 5v _signal_ (so the Arduino knows the car is now switched off) but it will need an independent power source).
If you really want to do the latter, email me for more details. Or try the 1F (or 2F, 3F) solution if you think it worthwhile. Connec the cap across the Arduino's VCC and GND and get one with (at least) 5v5 rating. Higher voltage caps will be larger and more expensive.
@@RalphBacon Thanks for the detailed response and links. I've tried to reply several times but YT deletes my post if it contains a URL. I think there's a ready-made part that can do this what your Mosfet circuit does: a 2V-20V switch, controllable by applying voltage to its ON, OFF, or CTRL pins "Mini Pushbutton Power Switch with Reverse Voltage Protection, Pololu item #2808" (can't link to it). Also, I've just read that hooking a big capacitor to the car's 12V wiring is somewhat dangerous, because, during the initial surge into the capacitor, the car's wiring may "detect" it as a short or spike, and blow a fuse (or worse)
Indeed, large capacitors can be seen as a short circuit. But you want the capacitor on the 5v side anyway.
Which website was that item from, I've tried fleaBay and Banggood, neither has anything.
BTW You can add URLs by using this sort of approach: webmaster at jargongeneration dot com. Fiddly, but it works!
@@contrarian8870 its a bit old Q but little battery would be way better. Small Lipo and charger circuit and some logic that detects if car is on or off. All extra parts are so cheap nowadays
@@martynaslukas4340 Thanks, I already solved this soon after posting. I added an IR sensor near the front-most position ("P") of my gear shift. I always put the car in "P" after I've stopped driving, just before turning off the engine. So now Arduino knows when I've just finished driving and it has ~2 sec (enough) to finish its job., before I remove the key. Works with no change to my driving routine.
I live in AZ, I'd be reluctant to leave a Lipo in a car in case it explodes. It gets up to 150F (60C) in the sun in a car. BTW, I also 3D-printed some PLA parts for my gadget, but they melted in the sun:) I had to re-print in ABS for in-car parts (higher melting point)
Under what circumstances would you choose an electrolytic capacitor over one that is unpolarized?
Thanks for the great video.
Depends! When you say "unpolarised" do you mean an unpolarised (aka bipolar) electrolytic capacitor or just a standard multilayer ceramic?
If the latter, then most multilayer ceramic caps have a range of 10pf to 0.1uf (100nF). Sometimes a bit higher but that's it. Larger values, above 1uF, are usually electrolytics.
Electrolytic caps go from, say, 0.1uF (100nf) all the way up to several thousand uF and indeed F (Farad) sized too, these days. But most electronics engineers will call them the Spawn of Satan because they deteriorate over time and usage and eventually fail or get very "leaky". It's very important to never exceed the stated voltage of an electrolytic cap. Running a 6v cap at 5v is OK. But running a 6v cap at 9v is a recipe for disaster. Allegedly, some LED bulb manufacturers do this to ensure their bulb device fails after a few thousand hours (the LED would last much, much longer).
An unpolarised electrolytic cap (bipolar) is effectively two caps connected in series with their cathodes (or anodes) together. They are often used when the polarity of either end gets reversed, such as in speaker crossovers. A bit of a special use case.
Any good?
Thank You
You're welcome!
Absolutely fantastic vid thanks sir much appreciated it 👍🏻🇬🇧 will you ever do a vid on 125khz RFID transmitting?
I cover RFIDs in video #34, Danny, is that what you mean?
Ralph S Bacon yes sir thanks I have a drone project incorporating one of my arduinos where I’m trying to read a RFID from a long distance say around 5-10 meters how would I energise a tag from such a distance? Please can you help me and my son he’s 14 and a big fan loves your arduino vids
Correct me if I'm wrong: the DECOUPLING cap doesn't actually send the noise to ground, but rather it acts as a buffer/shock absorber, and then re-releases the 'noise' back into the line but in a more flattened form?
Depends on the frequency of the noise I guess. High frequency noise will short through a cap rather than charge it
A decoupling capacitor routes the signal (noise) to ground.
Awesome lesson, thank you. Can I replace a 0.1uF capacitor with a 1uF on ESP32 VCC and GND? If so, would it has a satisfatory result, as decoupling function?
Normally it is best to keep the 100nf cap and put a bigger cap in parallel. The cap needs to work with high frequency spikes and the ceramic caps work better for this. So it's quite possible that you will use both, the 10uf or so providing a store of energy cloce to the chip.
It should work, but years of experience by those more knowledgeable than me have decreed that 100nF is the optimal value for size, noise suppression into the MHz territory and not being a burden on the power supply at switch on. For mucking about on a breadboard I'd use a 1uF if I had no 100nF but for "production" use always a 100nF. The reply by Embedded Hobbyist is true for things like voltage regulators but not really necessary for integrated circuits - but the datasheet for the device will always tell you what is recommended.
Hey Ralph. What’s the app you are using to make those nice drawings? Do you make them in real time? And do you use a mouse or a touchscreen or a graphic tablet to make them? I just ask because this could be really handy for my new day job I’ll be starting soon.
I'm using the standard Microsoft Whiteboard app on my Windows 10 PC, controlled by a (cheap) graphics tablet: amzn.to/3caEWje
Oh, it was cheap (£23) when I bought it, more than doubled now. It might come down again.
Ralph S Bacon ok this sounds nice. And as I already have a windows tablet I can try this out without buying anything else. Thank you Ralph.
Thanks for this - very helpful and the table is definitely going to be useful.
Any thoughts on tantalum capacitors?
Glad you liked this, Robert^2. Tantalum caps give a high(er) capacitance per cubic mm than most others, are very stable, small for their capacitance, and some are not polarised (most are though). What you do have to be *very careful* about is the voltage rating (I'm a fine one to talk, given that destroyed electrolytic in the video) as they will literally explode (and go short circuit) if overdriven; best to derate the max voltage to about 50% of stated.
@@RalphBacon I read that electrolytic capacitors sort of rot after a while. Is this avoidable? Many thanks
Electrolytics do deteriorate, as they dry out. A common problem in PSUs and audio amplifiers. From a design perspective you can mitigate (but never eliminate) this by placing electrolytics away from sources of heat on the PCB (eg transformers, power transistors), underrate the voltage (so use a 63-volt cap for a 35v supply) and by using top quality, branded components. Manufacturers look for a 10-year life for their products but consumers often want much, much longer!
Mmmm cookie capacitors :D
It was yummy!
What's with the American spelling of ANALOG at 5:20? I'm sitting here in California watching you write, preparing myself to do the conversion in my head ... but then you failed to put the "UE" on the end. I don't even know what's real any more. (insert smiley)
The British spelling of _analogue_ and _programme_ and many others is definitely falling out of favour (but _favor_ it is not). We have become corrupted by our colonial cousins.
@@RalphBacon _Charge_ on Ralph! _IC_ you have the _capacity_ to _resist_ !
Thank you, informative video as always,
In one project I did, the instructions said to connect 2 capacitors one ceramic and one electrolytic,
does this make any sense?
Yes, it's often the case to connect a 100nF multilayer ceramic together with a 1µF (or more) electrolytic in parallel. Together they cover a very wide frequency band so can kill noise well, and the electrolytic can also help prevent voltage sags if there is a sudden demand (for a few milliseconds).
@@RalphBacon Got it :). Thank you
I am afraid that you are a bit wrong about the reason for decoupling capacitor. It is not the noise from the power supply that is the problem. That you filter away at the power supply.
Even when you run the Arduino on a battery, you still need decoupling capacitor. The problem lay within the IC (arduino).
When the transistors inside the chip starts to work, they draw power instantly. The power lines on the board can't keep up with that burst and the IC will starve and probably shot down ever so briefly and give all sorts of problems. That is why the capacitor is there, to store energy for that brief moment.
Actually the 2 x 100nF capacitors placed close to the IC on an Arduino board are actually there to filter supply noise. The capacitors give high-frequency noise signals a low-impedance path to ground, they are not there for instantaneous power draw as the current demands are not that high.
@@Fifury161
The capacitor on the analog Vcc pin (supplies the ADCs) is there to filter external noise (from the supply or any other "noise generator" in the circuit). You should not only use the capacitor but also some inductance to create an LC low pass for the AVcc pin.
The capacitor on the digital Vcc pin (supplies all the rest of the chip) is there to prevent noise getting from the micro to the rest of the circuit and to prevent the micro from randomly failing because of power rail dips created by its own operation. Noise created on the Vcc pin by switching IO pins is significant (after all an AVR for example can go up to 200mA, or higher, if you ignore the specs). Even normal operation (without IO changes) will create power rail noise. That's what that cap is there for.
The caps are to:
(1) Prevent noise _entering_ on the VCC line
(2) Prevent noise _exiting_ on the VCC line (all that digital switching)
It's most important to separate the digital VCC and analog VCC on the bare chip, ideally with another 1µF cap on analog VCC - anything entering here will just give more noise on the analog pins (assuming you are using them for analog) and we know how noise-sensitive they can be.
Power reservoir caps are as I showed in the demo, wired close to the chip and anything from 1µF to 100µF. Datasheet will tell you if you need them.
Wall wart PSUs are the worst. I'm currently experimenting with ferrite beads (amongst other things) to see what it takes to get a stable, noise-free +5v from one of those!
@@superdau I pointed out that these capacitors have a 100nF value. That's significant; if you do the maths you will realise the value is not to provide instantaneous power, but to filter supply noise...
I am confused by the decoupling discussion. You say the noise goes through the capacitor to ground but I thought current didn't go through capacitors, just in and out on the one side - which is why they are drawn with the gap.
Mark, you are both correct and incorrect. In the DC world a capacitor does not allow DC to flow through it, it charges and discharges. In the AC world, alternating current flows through a capacitor. The capacitor has a "resistance" to AC called capacitive reactance that is a function of the capacitor's value and the frequency of the AC applied. Noise in a DC environment is alternating current - even though it doesn't change polarity - it does alternate from one voltage level to another (albeit randomly) and so the capacitor conducts it to ground.
David V has pretty much answered this. Any non-DC voltage can find its way past a capacitor, whether that is noise, a signal, music or AC voltage. Depending on the cap's value, the max frequency of what will pass is determined. But that's audio, not Arduino!
Hi Ralph. Again a very informative video. I did not know about the DC block usage. One thing I am wondering for some time now. If they specify use a X farad capacitor for you project they hardly ever specify the voltage. So is the voltage related at all to the capacitance? (farad is the unit for capacitance right?) As I see it the higher the voltage of a cap the longer it you need to charge it to get to that voltage? How to say this. Say the max voltage in the project will be 5 volt. Does it matter if they say you need to use a 47 uF cap if you use a 10volt or a 50 volts cap? (besides the size of course).
the voltage of a capacitor is the highest the dielectric can withstand before shorting out. it jumps the gap like a spark plug for an analogy.
@Hans De Groot To answer your specific question ... NO it doesn't matter if a 10v cap is specified but all you have to hand is a 50v one (or a 100v or 1000v. Depending on type of capacitor though you MAY need to pay attention to the ESR (Equivalent Series Resistance), leakage and frequency capabilities. For general LOW speed operation it's typically a non issue, but like Ralph said the specific circumstances may dictate specific values.
In the 45 years I've been an electronic engineer and 48 years of being a member of the IET I have been very fortunate in only experiencing an over-volted electrolytic capacitor twice! The first was whilst working for an audio amplifier company in Bristol - Radford Electronics, a name probably familiar to HiFi buffs that go back that far - there were several amplifiers on soak test (without their covers) and one started making a very high pitched whistling noise. I immediately reached over to switch it off but as I did so a large 80 volt rated power supply capacitor's top vent blew and sprayed my bare forearm with 100 degree plus electrolyte!! Very nasty, large burn and weeks to heal. NOT a pleasant experience!
The second was when another power supply capacitor EXPLODED out of the Marshall 100 watt amplifier under repair & test in which it was sitting and its aluminium foil and paper contents spiralled 40 feet across the small hall at Uni in which we were working, missing myself and a colleague by literally inches at head height. Loss of eyesight and a severe burn through scalding electrolyte was a real possibility ... for both of us. We were lucky!
As Ralph rightly highlighted NEVER, NEVER, NEVER, overvolt an electrolytic by even small amounts. They get extremely hot, extremely quickly in an avalanche effect and can and DO explode! Don't just take for granted the normal working voltage expected. Downstream components can fail, removing load and allowing a much higher voltage to suddenly and unexpectedly appear. That's what happened in the initial case above and the design was altered to have a 100 volt capacitor instead.The second was an out of spec PSU that had to be overhauled and repaired.
One other point. There are such things as non-polarised electrolytic capacitors, not very common if in use at all today but typically found in speaker cross-over filter circuits from the 60's to late 70's to my certain knowledge.THEY MUST be replaced with the exact same type i.e. non-polarised as they too can easily explode. If exact replacements cannot be found do not be tempted to fit near equivalent values a the cross-over will likely sound terrible when fitted to its designed for speaker. Unavailability will require a completely new cross-over design and/or replacement.
@@@boblewis5558 Clear. Stay well under the cap rating. Like at least 1 third below it. And never touch the pins of the very big capacitors from the old crt tv's after the tv has been on that day. They can hurt like hell. :) I have see websites with the complicated formulier that look like rocket science to me. I just thought things had to do with frequeny and stuff. Ie the small ceramic nano Farads caps are often used for filtering high frequency noice from power lines and the bigger micro farad onces for filtering out the lower frequencies. I thought that had something to do with how fast the reach their max capacitance (charge?) Thank you for the story. Did not think of the caps as bobs with a payload until now.
I was thinking of trying to make a buck converter. I am waiting for 160 volts caps from china. I think I can not go wrong there. But suppose if I would try to make a boost converter and my arduino code is wrong the volts could just run away until something explodes.
The value of capacitor, in microfarads (uF), determines how much charge it can store. The voltage rating is the maximum voltage it can stand before exploding like mine did. Larger voltage capability (eg 63V) just means a physically larger capacitor, no other benefit to us Arduinites. For smaller values (non-polarised, multilayer ceramics like I showed) the voltage rating is always higher anyway.
@@RalphBacon So unlike a rechargeable battery that is full when it reaches say 4.2 volt for a lithium ion you can fully "charge" a capacitor by just putting 1 volt on a 63volt cap?
I've never seen malted moo cows with a filling before. Where did you find this diabetes inducing delight?
It's a secret stash I have, but I can't remember where I bought them from, sorry. In the UK for sure.
Does the value of a blocking cap depends on the frequency and Zin?
Different value caps do allow different frequencies to pass (higher values allow lower frequencies) but it also depends on the voltage of the signal too. A lower value cap is fine for small signals. A much higher one is required for, say, output to a loudspeaker.
Had to pause video 30secs in to go on hunt for Malted milk biscuits. I don’t have any ☹️
I'm so sorry about that. Next time, be prepared!
One 100 gram, non-polarised Biscuit = about 2000 kilojoules = 160 *Farads* at 5 Volts.
About the same in calories too, Nick.
I am enjoying this series because it gives me a foundation to understand circuits. Protecting the GPIOs would be a good useful video also I'm sure you may be building up to it but I'm guessing it needs to be in most projects. I"m working this out now for first D1 Mini 8266 3.3v project. I am using this link www.thebox.myzen.co.uk/Tutorial/Protection.html .
Glad you like the series, Danny. Be careful with the ESP8266, it is easy to forget that 3V3 is the maximum voltage the pins will tolerate. Use a level shifter or voltage divider with resistors. Or just use 3v3 modules designed for the ESP8266 D1 Mini (they all plug in together, see my Home Alone project).
@@RalphBacon Thanks for the advice. I'm using the i2c ADS 1115 with a voltage divider and a mosfet module. I will keep a sharper eye out. Thanks again for all the work you put in to the videos.
If an LED needs a resistor, why don't they build it in the resistor?
because the size of the resistor needed varies with the voltage used.
They do if you buy led indicators with a stated voltage. E.g. 12V or 24V indicators then the correct value resistor is built in. But for normal things you just calculate the required value. (Supply - foward voltage of led)/ current you want. So if you have a 3v led and a 5v supply and you want 5mA through3the led. (5-3)/0.005
Explained perfectly by these other knowledgeable Arduinites.
@@RalphBacon I'm more of a microcontrollerphile
Good video ! I love arduino, on my TH-cam Channel I try bluetooth module !
Great 👍
Malted milks with cream in between! If that's not against the law it ought to be.
And using it as a model for a capacitor should be a chargeable offence.
Guilty as charged. But I have no regrets. I'd do it again.